Euromed Research Center. Engineering Division, Euro-Med University of Fes (UEMF), Route de Meknes, Rond-point de Bensouda. 30070 Fès, Morocco; Centre for Education and Research on Macromolecules, CESAM Research Unit, Chemistry Department, University of Liege, Sart-Tilman B6a, Allée de la Chimie 4000 Liège, Belgium; Laboratory of Organometallic and Macromolecular Chemistry-Composites Materials, Faculty of Sciences and Technologies, Cadi Ayyad University, Avenue Abdelkrim Elkhattabi, B.P. 549, 40000 Marrakech, Morocco.
Centre for Education and Research on Macromolecules, CESAM Research Unit, Chemistry Department, University of Liege, Sart-Tilman B6a, Allée de la Chimie 4000 Liège, Belgium.
Carbohydr Polym. 2020 Feb 15;230:115634. doi: 10.1016/j.carbpol.2019.115634. Epub 2019 Nov 21.
Simultaneous condensation of aromatic aldehydes (ArCHO; x = 1-4) on chitosan biopolymer (CS) affords, after water-evaporation, structurally-conjugated aryl-functionalized CS-Ar-f films. Similarly, cooperative assembly of two-dimensional nanometric graphene oxide (GO), aromatic aldehyde and chitosan provides transparent, flexible and crack-free aldehyde-functionalized, ternary-reinforced CS-Ar-GO-f nanocomposite films. Homogenous films were obtained using ortho-hydroxybenzaldehyde Ar while the para-hydroxybenzaldehyde Ar was prone to packing inside. Textural and mechanical properties were investigated and expectedly, significant improvement was found for CS-Ar-GO-f because of the great dispersion of the aromatic and the presence of the filler. The sensitivity of unsaturated CN imine bond to hydrolysis was explored for triggering controlled release of aromatics from the as-prepared films. All of them were found to induce a time-dependent aromatic release. It has been moreover observed that the release was significantly delayed in CS-Ar-GO-f compared to CS-Ar-f, a fact attributed to the interplay of the ring with the basal and edges of graphene oxide, through π-π stacking and additional hydrogen bonding interactions. This finding shows that beyond the conventional wisdom using fillers for improving thermal and mechanical properties, the tiny carbon sheets can act as a regulator for aldehyde release, thereby providing a way for more controlled chemical delivery from confined nanocomposites.
同时将芳香醛（ArCHO；x = 1-4）冷凝在壳聚糖生物聚合物（CS）上，在蒸发水后，会得到结构共轭的芳基官能化 CS-Ar-f 薄膜。同样，二维纳米氧化石墨烯（GO）、芳香醛和壳聚糖的协同组装提供了透明、柔韧且无裂纹的醛官能化、三元增强 CS-Ar-GO-f 纳米复合材料薄膜。使用邻羟基苯甲醛 Ar 可以获得均一的薄膜，而对羟基苯甲醛 Ar 则容易在内部堆积。对其进行了纹理和机械性能的研究，由于芳香族物质的良好分散和填料的存在，CS-Ar-GO-f 的性能得到了显著提高。不饱和 CN 亚胺键对水解的敏感性被用来触发从所制备的薄膜中释放芳香族物质。所有的薄膜都被发现会引发时间依赖性的芳香族物质释放。此外，与 CS-Ar-f 相比，CS-Ar-GO-f 的释放明显延迟，这一事实归因于环与氧化石墨烯的基面和边缘之间的相互作用，通过 π-π 堆积和额外的氢键相互作用。这一发现表明，除了使用填料来提高热学和力学性能的传统观念之外，微小的碳片可以作为醛释放的调节剂，从而为从受限的纳米复合材料中更受控的化学输送提供了一种途径。
